I'm not sure about the option to be able to start the car with no one in it. isn't it illegal in the U.K. to leave a vehicle unattended with the engine running?

According to my dealer, the preheating is done without starting the engine. It uses electric to preheat for a max of 15mins (you can select less on the app). Also nifty to cool the car down in the summer

The preheating, if it is anything like my RRS, is all part of the app on your phone that will give you information about the status of your car. Basically you are able to start you locked and alarmed car and set the temperature to be achieved, and all remotely from anywhere in the world.

Just a note to the person earlier in the thread about VOC providing a wireless hotspot, it does but you have to add another SIM card with data allowance, people in the U.K. tend to be using 3 data sims which cost about £40 for 24GB which lasts 2 years.
VOC has a built in sim but this is only used for VOC actions. When you add another sim this gives to access to wireless hotspots, traffic data etc. VOC then uses this sim for its use as well. If you don’t want to buy an extra sim you can tether your phone to the car and use that for hotspot and applications data.